Automatic guide vane locking device for a hydraulic machine



June 28, 1960 c. F. AMBRoz AUTOMATIC GUIDE VANE LOCKING DEVICE FOR A HYDRAULIC MACHINE United States Patent OF AUTOMATIC GUIDE VANE LOCKING DEVICE FOR A HYDRAULIC MACHINE Charles F. Ambroz, Milwaukee, Wis., assiguor to Allis- Chalmers Manufacturing Company, Milwaukee, Wis.

Filed Apr. s, 195s, ser. No. 726,237

s claims. (ci. 25a- 122) The present invention relates generally to improvements in hydraulic turbines Iand speciically to a hydraulic turbine having improved means for locking the guide vanes in the closed position.

Heretofore in hydraulic turbines automatic guide vane locking mechanisms have been constructed in various ways. One prior art construction consisted of a spring actuated latch engaging the operating ring of the guide vane operating mechanism when the guide vanes were in the closed position. Another type of guide vane locking mechanism incorporated the use of va hooked pawl to engagek the guide vane operating rod when the operating rod was in the closed position.

The increased use of .automatic guide vane locking de.- vices on large hydraulic turbines presents engineering problems inthe automatic `guide vane locking devices heretofore used. The automatic guide vane locking device consisting of a pawl tripped by pressure from a uid servomotor and spring vbiased into .a lockingv position on the guide vane ring became impractical as turbines increased injsize-because of the'distance between thehuid servomotor actuating the guide vane operating mechanism and the pawl to automatically actuate the locking device. As turbines increased in size and capacity the, water pressure on the guide vanes and the fluid pressure of the servomotor, which operates the guide vane mechanism, either singly or in combination placed an eccentric load upon the guide vane operating rod,- and the hook pawl type of automatic guide vane locking mechanism became inadequate because the forces exerted on the guide vane operating rod tended to bend the guide vane operating rod away from the hook pawl unlessthe rod was made larger than a convenient size and of material of great strength.

ln the present invention it is proposed to provide automatic guide vane locking means which will engage the guide vane operating rod from two sides keeping the load ofthe forces on the rodA symmetrical vand engaging the operating rod in a manner which positively prevents the guide vanes from opening accidentally as by a failure of the guide vane operating mechanism.

In a preferred embodiment of the present invention, i

the guide vane locking action is `accomplished by providing a pair ofpawls with'diametrically opposite pivot points about 'a rod of the guide vane adjusting means; Pawl actuating means are provided to move the pawls convergingly toward or divergingly `away from the -guide vane operating rod and thereby into and out of engagement with an adjustable detent means on the operating rod. The pawl actuating means are able to pivot the pawls convergingly toward each other and the shaft which is between the .pawls so that the'pawls simultaneously engage diametrically opposed portions of detent means when the guide vane operating rod is Vin the guide vane closed position to prevent movement of the guide vane operating rod 'in a yguide vane opening direction. The pawls are pivoted away from the shaft to disengage the detent means Patented June 28, 19611 ice on the shaft and release the shaft for guide vane opening movement in lresponse to operation of turbine starting means. Pawl disengaging action operates a switch that in turn operates a control device that actuates van operating mechanism for vane opening action of the vane adjusting means. Thus the pawls -must irst disengage before any vane opening action can take place. Furthermore, the pawls are biased toV engage the detent means on the shaft and it is only by the positive operation of the turbine starting means that the pawls are released. Thus if for example, as in the preferred arrangement that will be described, the guide vanes are operated by a uid pressure operated servomotor, a failure of the uid pressure supply system will not make it possible for the guide vanes to open accidentally.

it is therefore an object of this invention to provide in a hydraulic turbine improved automatic guide vane locking means which positively lock the guide vanes in the closed position.

Another object of this invention is to provide in a hydraulic turbine automatic guide vane locking means which simultaneously place a symmetrical load on the guide vane operating rod.

Another object of the invention is to provide in a hy'- draulic turbine improved automatic guide vane locking means which will insure that the guide vanes must be positively and intentionally unlocked before any vane opening action can take place.

Another object of the invention is -to provide in a hydraulic turbine improved automatic guide vane locking means which will insure that no vane opening action can be initiated until pawls that lock the vanes have been disengaged so that it is not possible for the vane operating servomotor to place a load on the pawls when thepawls are in vane locking position.

Other objects will appear hereinafter as :a description cl the invention'proceeds.l The novel features of the invention and how the objects are attained will appear more fully from this specication and, the accompanying drawings showing ian embodiment of the invention and forming a part of this application and all of these novel features are intended to be pointed out in the -appended claims.

In the drawings: Y

Fig. 1 is a fragmentary plan view of `a portion of a hydraulic turbine with portions of the covering structure cut away to show parts of a guide vane adjusting mechanism and their relationship to each other; g

Fig. 2 is a plan View of a portion of the vane actuating mechanism partly in section; and i Fig. 3 is a side view-of the structure shown in Fig. 2.

In Fig. l a portion of a hydraulic'rturbine 1 isA shown as having yadjustable vanes: 2 for controlling the'ow of water through the turbine. Vanevadjusting means f are shown, including an axially movable shaft 3 pivotally connected to guide vane operating ring 4. Guide vane operating ring 4 has a pluralityv of ilangesS connected" by guide vane links 6 to lever 7A which in turn isconnected to movable spindle 8 of adjustable guide vanes 2. The axiallyV movable shaft 3 is lactuated by operating means shown as a servomotor 9 which in turn is actuated bya conventional speed governor-(notl shown). -When -the speed governor (not shown) calls for a' change in the position of the adjustable guide vanes 2, servomotor 9 actuates shaft 3 which rotates guide vane adjusting ring 4, and guide vanes operating ring 4 through anges'S will move guide vaneV links 6 and guide vanes 2. i l l Servomotor 9 has a piston 10 and a piston rodj11 which is connected to the shaft. Fluid pressure conduits 12 and 12a having ports-,13 and levare shownconnected to servomotor 9. Control means, shown in Fig. 3

to rotate levers V7,- spindles-18,

adjustable l'nut- 15 to secure it in a preselected position;

Pawlf means shown in Fig. l as av pair of pawls 18 arranged respectively onY oposite sides of axially movable shaft? 3vare supported by shaft 19 shown in Fig. 2 as being connected' to rocker armsY 20. Rocker arms 20 are conncted to pivotipawlsI 178 about the axis of shafts 19. The fxis of each of the'- shafts 19 is perpendicular to axially movable shaft 3'.

Fig. lfurther shows a member 21 lixed to servomotor 9 and arranged to engage threaded nut 15 at a preselected position on the shaft 3 when axially movable shaft 3 moves in a closing directionl thereby limiting the vane closing movement of the axially movable Vshaft 3. The limiting of the closing movement of shaft prevents inilrions pressure from being placedon the engaging'edges fguide vanes 2 when in the closed position. Rocker arms shown in Fig. 2 are biased toward each other by spring 22 to rotate rockerV arms 20' and shafts 19 and pwls 18150 that pawls 18 pivot convergingly toward each.' other and toward axially movable plate 3l to lcrgagev'vith threaded guide vane lock bearing plate 16 Y when said axiallyv movableshaft 3 is in a vane closed position. A second biasing Vmeans consisting of a second :ishaY 'solenoidiop'e'r'ate'dicontrolrvalve 35', are provided toy l 4 f and flanges 5 connected to guide vane operating ring 4 Yto move in a counterclockwiseV direction.vv VGuide vane link 6 connected to angesS and lever 7 connected to guide vane ring 4 are moved by the counterclockwise rotation of guide vane operating ring 4 causing spindles 8 to rotate and move vanes 2 to the open position.

When piston 24 of theusecondservomotor 23 has moved to its furthermostv position toward4 rocker arm 2 0v and for anyreason the turbine mustbeY shut downfor an emergency failure occurs th'e'iluidv pressure is drained. from the second-r servomotor 23 through conduit 30 bya reversal of solenoid valve 33.V Conduit 31. appears for the purpose of draining off leakage past piston 24 of second servomotor 23. Spring22 willibiasrocker arms 2t) in a direction opposite'tothedirection of their disengaging movement causing shafts 19 to rotate in a direction opposite to the direction of their disengaging movement and causing pawls 18 to pivot convergingly toward each other about shafts 19.

' When the speed? governor or an emergency shutdown calls for the vanes to move to the closed position, Huid pressure is'admitted throughv fluid pressure conduit 12a and port 13 shown in Fig. l to the guide vane closing side of piston 10 and fluid pressure isdrainedY from the tlid servomotor 23, piston 24 and piston rod 25, is con- Y iecftd'toirocker arms 20 by link 26 connected to piston inl'e'tffcondtiit 30Jand. exhaust conduit 31. Conduit 3|)Y is connected to a fluid pressure source (not shown) and I will admit'uid pressure to servomotor23 when the turbine is to be'st'arted by 'actuating Vreversible solenoid valve 33; Whenrpiston rod 25l reaches the position furthermost toward rocker arms 720, it will trip means shown Vin Fig. 2 als Valmit l"switch 34 connected to a solenoid operated control valve 35` permitting iluid pressure to be admitted fo Vthe vane opening side of servomotor 9, thereby Ydelaying the application of fluid pressure to the vane opening side of the piston `10 so that servomotor 23 will disngage'pawls 18' from detent plate 16 before pressure can-be admitted to servomotor 9.to begin moving the 'vanes in an opening direction. Y-

The operation of "the mechanism will be described beginnin'g withthe position shown in Fig. l wherein the 'vanes 2 are closed and the detent nut 15 nd plate 16 are-'lockedrin postion'between thepawls 18 and the inember" 11.5 wht-.nime hydraulic turbine is Vte be' started,

vane opening side of piston `10 throughconduit l12 causing piston 10 to bias piston rod 11 and guide vane voperating rod 3 in the closing direction. Pawls, 18 are in the closed position and rideup and over nut 15 'andl plate 16 and snap into positionV against threaded guide vane lock bearing plate surface 36 when the vanes are closed thus preventingl any movement# of axially movable shaft 3 in the opening direction. At the same time,k surface 37 of adjustable threaded Ynut V15* ,enga-ges member 21 preventing further movement of axially movable's'haft 3 in the guide vane closing direction and preventing excessiveforce's from `being applied tothe engaging edgesof guide vanes 2. Axially movable: shaft'S when moving-in the-guide vane closing direction rotatesV guide vaneV operating' ring 4in the clockwise direction, also rotating flanges 5 connected to guide vane operatinglring 4j in'the'clockwise direction. Guide'vanelinksh and levers 7 connected to flanges 5 rotate spindle 8 and guide vane 2 to the closed position. V Y Y Because the Ypawlsv 1,8 will'not -rnove divergingly away from each otherfand out ofV` engagement with the plate 16 except when second servomotorl 23 is biased byzluid pressure, the vanes will not be opened accidentally as a l result of 'a failure ofthe duid pressure system. Furtherlnid'vlvev-33 isY actuated and fluid passes through Y conduit V30 shownv in Fig. 3 -to Ysecond servomotor 23. PiSt'onfM Yand piston'rod 25 will move to thefurthermost position-'axially toward rocker arms 20. Links n26 fand-27 coact withV pistoni-24v and piston rod 25 to which is'conected vwhile they are moving'v to the position rthermors't axiallyjtoward rocker arms 20. and `pivot rocker A2l) in opposite directions, causing shafts 19 fofroatein kol'ipcsit'e directions and; pawls'v18 to pivot butsha'ft -19 divrg'ingly away from each otherV and vlvf35 `to release nidgpressure through conduit 12 Y to the vane opening side of piston y10 to bias pistonY 10 in the 'vane opening direction. When piston 10 vmoves in Vvaine openingdireetion piston rod 11 and shaft 3 move more, no vane opening Vaction can be initiated until" the pawls have Ybeen disengaged so that it is not possible for the vane operating Vservomotor 9 to place a load on the pawls 18 when the pawls arein a vane locking position. And still further', the arrangementl insures .that the pawls 18 will engage `and disengage the de'tent-'plate 16 simultaneously so Vthat forces onfshafts 11" and '3f will be'- balanc'ed'and no bending fof the 'shafts will take'place.

These and other features, and advantages/will be obvious to those skilled in this -ar`t'. It will 'beobviousto those skilled in thisart that the illustrated embodiment of the invention provides a newV andY improved guide vane locking means for lockingl the guideY vanes in the Yclosed posi-tion and accordingly accomplishes y theobjects of the invention. On Vthe other `hand it will Valsol'heobvious to those skilled in the art that theillustrated-embodiment of the invention may be variously changed and m'odiied or Yfeatures thereof singly or collectively Vernbodiedfin'"other jnot limited thereto.

What is claimed is: Y. p

1.Y In a hydraulic turbine, Yadjustable vanes connected to4 said turbine forV controlling the flow of water through said turbine', Vvane 'adjustingfneans connected toY s'aid vanes, first operating means connected to said adjusting means vfor moving, saidvanes between an open and a closed position, .control means connected to said first operating means, said control means being operative to activate said iirst operating means, pawl means pivotally connected to saidirst operating means, biasing means connected to said pawl means and biasing said pawl means to pivot to engage ywith said vane adjusting means and prevent vane opening motion of said vane adjusting means, second operating means connected to said pawl means operative to overcome said biasing means and pivot said pawl means to disengage said pawl means from said vane adjusting means, and switch means connected to said control means and said switch means positioned to engage said second operating means when said second operating means acts to disengage said pawl means, said switch means :being operative upon engagement with said second operating means to energize said control means to activate said first operating means.

2. In a hydraulic turbine, adjustable vanes connected to said turbine for controlling the :flow of water through said turbine, vane adjusting means including an axially movable shaft connected to said vanes, rst operating means connected to said shaft for moving said shaft to move said vanes between an open and a closed position, control means connected to said rst operating means, said control means being operative to activate said operating means, a pair of pawls arranged respectively on opposite sides of said shaft, means connected to said rst operating means for supporting each of said pawls -for pivotal movement about an axis perpendicular to said shaft, biasing means connected to said pawls, said pawls being biased to pivot convergingly toward each other and said shaft to engage ywith said shaft to stop vane opening motion of said shaft, second operating means connected to said pawls and operative to overcome said biasing means and pivot said pawls divergingly away from each other and said shaft to disengage said pawls from said shaft, and switch means connected to said control means and said switch means positioned to engage said second operating means -when said second operating means acts to disengage said pawl means, said switch means being operative upon engagement with said second operating means to energize said control means to activate said first operating means.

3. In a hydraulic turbine, adjustable vanes connected to said turbine for controlling the flow of water through said turbine, vane adjusting means including an axially movable shaft connected .to said vanes, a iirst tluid pressure operated servomotor having a piston connected to said shaft to move said vanes in an opening direction when uid pressure is delivered to one side of said piston and to move said vanes in a closing direction when uid pressure is delivered to the other side of said piston, a pair of pawls arranged respectively on opposite sides of said shaft, means connected to said first fluid pressure operated servomotor supporting each of said pawls for pivotal movement about an axis perpendicular to said shaft, :biasing means connected to said pawls, said pawls being biased to pivot convergingly toward each other and said shaft to engage with said shaft to stop vane opening motion of said shaft .when said shaft is in a vane closed position, a second uid pressure operated servomotor having a piston assembly connected to said pawls and operative vwhen fluid pressure is delivered to said second servomotor piston to overcome said biasing means and pivot said pawls divergingly away from each other and said shaft to disengage said pawls .from said shaft, iluid pressure conduit means connected to both of said servomotors, a control valve connected to said first servomotor to admit operating uid to said first servomotor, and a limit switch connected to said control valve and said limit switch positioned to engage said piston assembly of said second servomotor upon pawl disengaging action of said second servomotor, said limit switch being operative upon engagement with said piston 'assembly to.

operatesaid control valveto admit fluid pressure to said vane opening side of said,l rst servomotor piston.

4. In a hydraulic turbine, adjustable vanes connected to said lsurbine for controlling the ow of water through said turbine, vane adjusting means including an axially movable shaft connected lto said vanes, a rst tluid pressure opera-ted servomotor having a piston connected to said shaft to move said vanes in an opening direction when iin-id pressure is delivered to one side of said piston and to move said vanes in a closing direction when lluid pressure is delivered to the other side of said piston, a pair of pawls arranged respectively on opposite sides of said shaft, means connected to said rst tluid pressure operated servomotor supporting each of said pawls for pivotal movement about an axis perpendicular to said sha-ft, biasing means interconnecting said pawls, said pawls being biased to pivot convergingly toward each other and said shaft .to en-gage with said shaft to stop vane opening motion .of said shaft when said shaft is in a vane closed position, a second fluid pressure operated servomotor having a piston assembly connected to said pawls and operative when fuid pressure is delivered to said second servomotor piston to overcome said biasing means and pivot said pawls divergingly away from each other and said shaft to disengage said pawls from said shaft, first fluid pressure conduit means connected to said first servomotor including a solenoid operated control valve connected to said -flrst servomotor to admit operating uid to said vane opening side of said rst servomotor piston, and a limit switch connected to said solenoid operated control valve, said l-imit switch being positioned to engage said piston assembly of said second servomotor after pawl disengaging action of said .second servomotor, said limit switch being operative upon engagement Iwith said piston assembly .to energize said solenoid operated control valve to admit fluid pressure to said vane opening side of said first servomotor piston.

5. In a ,hydraulic turbine, adjustable van-es connected to said turbine for controlling `the ilow of water through said turbine, vane adjusting means including an axiallyV movable shaft connected to said vanes, a first fluid pres-` sure operated servomotor having a piston connected to said shaft to move said vanes in an opening direction when fluid pressure is delivered to one side of said piston and to move said vanes in a closing direction when fluid pressure is delivered to the other side of said piston, detent means mounted lon said shaft and adjustably posi- .tioned along Ithe axis of said shaft, a member mounted on said first iiuid pressure operated servomotor and arranged to engage said adjustable detent means when said shaft moves in said vane closing direction to a preselected position to adjustably limit vane closing movement of said shaft, a pair of pawls arranged respectively on opposite sides of said shaft, means connected to first uid pressure operated servomotor supporting each of said pawls for pivoting about an axis perpendicular -to said shaft, a biasing spring connect-ing said pawls to bias said pawls to pivot convergingly .toward each other and said shaft to engage with said detent means to stop vane opening motion of said shaft when said shaft is ina vane closed position, a second uid pressure operated servomotor having a piston assembly'connected to said pawls and operative when vfluid pressure is delivered to said second servomotor piston to overcome said biasing means and pivot said pawls divergingly away from cach other and said shaft to disengage said pawls from said detent means, ilu-id pressure `conduit means connected to said iirst servomotor including a solenoid operated control valve .connected to said i'irst servomotor to admit operating iluid to said vane opening side of said iirst servomotor piston, second fluid pressure conduit means connected to said second servomotor to move said second servomotor piston to disengagc said pawls, and a limit switch connected to said solenoid operated control valve, said mtor piston assemblyairterY,pawl-Ydaqrgggagigg;atgnz of said second seTvomQtQr, saidg-l-imit switch being qperative piston.

' References Cid in he. file of'rthis patenti UNIT-ED STATES 15M-Elvis;

2,436,372 Aver; K V Feb. 24,1948

FOREIGN PATENTS Canada J11n'e719, 1951 

